Run closed_world2_test using the normal compiler pipeline.

pkg/compiler/lib/src/library_loader.dart

Index: pkg/compiler/lib/src/library_loader.dart
diff --git a/pkg/compiler/lib/src/library_loader.dart b/pkg/compiler/lib/src/library_loader.dart
index 64879395edf2db6c9dc902e980f3a1833bde2282..12b91c4dc872c390c8bb57e9ab4672d2cc8088c1 100644
--- a/pkg/compiler/lib/src/library_loader.dart
+++ b/pkg/compiler/lib/src/library_loader.dart
@@ -846,20 +846,24 @@ class DillLibraryLoaderTask extends CompilerTask implements LibraryLoaderTask {
       bytes.removeLast();
       new BinaryBuilder(bytes).readProgram(program);
       return measure(() {
-        _elementMap.addProgram(program);
-        program.libraries.forEach((ir.Library library) => _allLoadedLibraries
-            .add(_elementMap.lookupLibrary(library.importUri)));
-        LibraryEntity rootLibrary = null;
-        if (program.mainMethod != null) {
-          rootLibrary = _elementMap
-              .lookupLibrary(program.mainMethod.enclosingLibrary.importUri);
-        }
-        return new _LoadedLibrariesAdapter(
-            rootLibrary, _allLoadedLibraries, _elementMap);
+        return createLoadedLibraries(program);
       });
     });
   }
 
+  LoadedLibraries createLoadedLibraries(ir.Program program) {
+    _elementMap.addProgram(program);
+    program.libraries.forEach((ir.Library library) =>
+        _allLoadedLibraries.add(_elementMap.lookupLibrary(library.importUri)));
+    LibraryEntity rootLibrary = null;
+    if (program.mainMethod != null) {
+      rootLibrary = _elementMap
+          .lookupLibrary(program.mainMethod.enclosingLibrary.importUri);
+    }
+    return new _LoadedLibrariesAdapter(
+        rootLibrary, _allLoadedLibraries, _elementMap);
+  }
+
   KernelToElementMap get elementMap => _elementMap;
 
   void reset({bool reuseLibrary(LibraryElement library)}) {
@@ -885,9 +889,7 @@ class DillLibraryLoaderTask extends CompilerTask implements LibraryLoaderTask {
         'DillLibraryLoaderTask.registerDeferredAction');
   }
 
-  Iterable<DeferredAction> pullDeferredActions() {
-    throw new UnimplementedError('DillLibraryLoaderTask.pullDeferredActions');
-  }
+  Iterable<DeferredAction> pullDeferredActions() => const <DeferredAction>[];
 }
 
 /// A state machine for checking script tags come in the correct order.